January 12, 2021—KB4598278 (Monthly Rollup)

Applies to: Windows Server 2012Windows Embedded 8 Standard

Improvements and fixes


This security update includes improvements and fixes that were a part of update KB4592468 (released previous December 8, 2020) and addresses the following issues:

  • Addresses a security bypass vulnerability that exists in the way the Printer Remote Procedure Call (RPC) binding handles authentication for the remote Winspool interface. For more information, see KB4599464.
  • Addresses a security vulnerability issue with HTTPS-based intranet servers. After you install this update, HTTPS-based intranet servers cannot leverage a user proxy to detect updates by default. Scans that use these servers will fail if the clients do not have a configured system proxy.

    If you must leverage a user proxy, you must configure the behavior by using the Windows Update policy Allow user proxy to be used as a fallback if detection using system proxy fails. To make sure that the highest levels of security, additionally leverage Windows Server Update Services (WSUS) Transport Layer Security (TLS) certificate pinning on all devices. For more information, see Changes to scans, improved security for Windows devices.

    Note This change does not affect customers who use HTTP WSUS servers.
  • Addresses an issue in which a principal in a trusted Managed Identity for Application (MIT) realm does not obtain a Kerberos Service ticket from Active Directory domain controllers (DCs). This issue occurs after Windows Updates that contains CVE-2020-17049 protections released between November 10 and December 8, 2020 are installed and PerfromTicketSignature is configured to 1 or higher. Ticket acquisition fails with KRB_GENERIC_ERROR if callers submit a PAC-less Ticket Granting Ticket (TGT) as an evidence ticket without providing the USER_NO_AUTH_DATA_REQUIRED flag.

  • Security updates to Windows App Platform and Frameworks, Windows Graphics, Windows Media, Windows Fundamentals, Windows Cryptography, Windows Virtualization, and Windows Hybrid Storage Services.

For more information about the resolved security vulnerabilities, please refer to the new Security Update Guide website.

Known issues in this update


Symptom Workaround
Certain operations, such as rename, that you perform on files or folders that are on a Cluster Shared Volume (CSV) may fail with the error, “STATUS_BAD_IMPERSONATION_LEVEL (0xC00000A5)”. This occurs when you perform the operation on a CSV owner node from a process that doesn’t have administrator privilege.

Do one of the following:

  • Perform the operation from a process that has administrator privilege.
  • Perform the operation from a node that doesn’t have CSV ownership.

Microsoft is working on a resolution and will provide an update in an upcoming release.

How to get this update


Before installing this update

We strongly recommend that you install the latest servicing stack update (SSU) for your operating system before installing the latest Rollup. SSUs improve the reliability of the update process to mitigate potential issues while installing the Rollup and applying Microsoft security fixes. For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions.

If you use Windows Update, the latest SSU (KB4566426) will be offered to you automatically. To get the standalone package for the latest SSU, search for it in the Microsoft Update Catalog

Install this update

Release Channel Available Next Step
Windows Update and Microsoft Update Yes None. This update will be downloaded and installed automatically from Windows Update.
Microsoft Update Catalog Yes To get the standalone package for this update, go to the Microsoft Update Catalog website.
Windows Server Update Services (WSUS) Yes

This update will automatically sync with WSUS if you configure Products and Classifications as follows:

Product: Windows Server 2012, Windows Embedded 8 Standard

Classification: Security Updates

 

File information

For a list of the files that are provided in this update, download the file information for update 4598278